Washington — Secretary of State Hillary Rodham Clinton informed Congress Friday that she would remove a controversial Iranian opposition group from the US list of terrorist organizations, drawing to a close a dogged de-listing campaign by the group and its high-profile advocates that stretches back to the Bush administration.

The de-listing of the Mojahedin-e Khalq (MEK) was not unexpected, since Secretary Clinton was under court order to decide by Oct. 1 whether to remove the group from a list it had been on since 1997.

Clinton had said her decision would be guided in part by the group’s cooperation in relocating hundreds of its adherents from a refugee camp in Iraq, and in recent weeks the State Department had signaled that the relocation process was proceeding toward resolution.

Under President Bill Clinton the MEK was placed on the terrorist list for the killing of six Americans in Iran in the 1970s and for a botched attack against the Iranian mission to the United Nations in 1992. Some Republican foreign-policy hawks charged the Clinton administration with listing MEK as a terrorist group in an effort to curry favor with the Iranian regime, but the group’s efforts at winning de-listing from the George W. Bush administration were unsuccessful.

The unrelenting de-listing campaign that began under Bush intensified under President Obama, with a number of prominent former officials from the Bush administration, including former Attorney General Michael Mukasey, taking up the group’s cause. Some prominent Democrats and former heavyweights from the Obama administration, including a former national security adviser, James Jones, also lent their name to the group’s cause.

The MEK began as a leftist organization opposed to the rule of the shah, and it initially supported the Iranian revolution. But many of its followers fled to Iraq after suffering under the revolution’s repression, and the group then sided with Saddam Hussein in the Iran-Iraq war – a move that many Iranians have never forgiven.

The MEK has renounced violence and its members in the US insist that members and supporters inside Iran have been instrumental in providing useful and sometimes blockbuster information on the Iranian government’s covert activities, particularly its nuclear program.

Several members of Congress were quick to laud Clinton’s decision – and to portray the group as transformed from a onetime opponent to a vital asset for the US in its dealings with Iran.

“The MEK long ago renounced violence, and in recent years has been actively working with US intelligence agencies to get information on activities inside Iran,” said Rep. Ted Poe (R) of Texas in a statement. “Recently, we have seen that the real terrorists are the mullahs of Iran and the tiny tyrant in the desert, Mahmoud Ahmadinejad, not the freedom fighters hoping for a democratic Iran.”

His colleague, Rep. Dana Rohrabacher (R) of California, bemoaned the group’s original listing as “a misguided attempt by the Clinton administration to gain favor with the government in Tehran.” He characterized the MEK as “Iranians who desire a secular, peaceful, and democratic government. Nothing threatens the mullah dictatorship more,” he added, “than openness and transparency.”

Just how the MEK is viewed inside Iran remains the subject of debate. Members and some high-powered supporters echo Representative Poe’s characterization of them as “freedom fighters,” but other Iranian opposition groups that have formed in the US in recent years insist that the group is intensely disliked in Iran and widely distrusted.

The years-long removal under UN auspices of more than 3,000 MEK members from Camp Ashraf in Iraq is almost complete, with the goal of moving the Iranian refugees to third countries.